A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
Operation of the gas turbine engine is controlled according to schedule of thrust settings. Engine operating parameters are modified and adjusted to provide the desired thrust setting according to the schedule. Different thrust settings are defined according to the schedule for different aircraft operating periods, such as for takeoff, climb, cruise and landing. Each operational period includes a different schedule of engine thrust, also referred to as a rating. Within each operating period adjustments are made to account for variations in temperature, pressure, altitude, aircraft weight and many other variable factors.
Moreover, each airframe manufacturer defines the desired thrust or rating schedule for each operating condition. Further, each airframe manufacturer may also require different rating schedules for different parts of the operating sequence from take-off to landing. The rating schedules are defined as part of an engine control program and are typically uniquely constructed for each engine and/or aircraft platform. Development of control programs can be costly and time intensive and therefore it is desirable to design a system that could be utilized for many different engine and aircraft platforms.